Text 1 What has been described as the largest ever ransomware attack-a cyber criminal scheme that locks up computer files until vicLims pay a ransom-holds the paradoxical disLinction of being both an outrageous success(in terms of its blast radius)as well as an abject failure(in terms of its h8ul).The malicious software spread so far and wide,jammed up so many IT networks and generated so much panic and chaos that the wronE;doers effectively undid themselves.On May 12,the world awoke to the beginnings of hundreds of thousands of old Microsoft Win-dows based computers"seizing up as Lhey subjected to a malicious software,appropriately called WannaCry.Within hours,the digital epidemic circled the globe like the Spanish flu,infecting ma-chines running outdated operating systems in some 150 countries,spreading across numerous homes and corporate networks.The attack,which relied on powerful tools believed to have been developed by the NSA and leaked online in April by a group of hackers known as the Shadow Brokers,wormed its way through businesses,hospitals and govemments,all of which found themselves suddenly locked out of their own systems.Researchers detected the wave quickly,and it wasn"t long before they picked up on the criminals"self-defeating mistakes.The attackers failed to assign each victim a separate Bitcoin wallet,researchers noted,a criiical error that meant they would not be able to easily Lrack ransom pay-ments.They neglected to automate the money collection in a way that would scale.And then there was the matter of the kill switch.No one is quite certain why the attackers coded a self-destruct burton into their software,yet that"s precisely what they did,Marcus Hutchins,a 22-year-old security researcher based in England who goes by MalwareTech,stumbled on the power plug largely by accident.After taking lunch on that Friday aftemoon,he inspected the malware and noticed a specific web address encoded within.Curious,he registered the domain for less than$11.This simple aci stopped the malware,killing the virus"ability to spread and buying Lime for organizations to upgrade their software and deploy protections.Researchers held that the attack was____
A.critical B.flawless C.defective D.invulnerable